A Design of Planar Reflective Linear-to-Circular Polarization Conversion Pattern Manipulation Surfaces with Enhanced Axial Ratio Bandwidth

In this article, a planar linear-to-circular polarization conversion pattern manipulation surfaces (LCPC-PMS) is designed. Firstly, the application and the structure is studied. Secondly, the patch element with variable microstrip length is analyzed, and the working condition is obtained based on equivalent circuit model. Then, the performance of the element is evaluated by calculation. To broaden the axial ratio (AR) bandwidth, fil- tenna design method is introduced to bring in extra minima. The 3dB AR bandwidth is thus broadened to larger than 3% in measurement. Finally, to verify our design concept, based on phased array theory, three prototypes are designed, fabricated, and measured. The three prototypes successfully steer the incident LP wave to the desired direction with circular polarization. The proposed linear-to-circular polarization conversion pattern manipulation surfaces is a promising candidate for 6G networks.